Quote Originally Posted by Six_Shooter View Post
When's the last time you did a tune up?

There's really no reason that a stock engine (assuming, since there's no indication otherwise), shouldn't pass emissions with a stock bin, though the lack of AIR system might be the culprit here and I'm surprised you haven't failed on that alone.
The AIR system was removed due to failed pump and the emissions system is being certified compliant to 1991 model which eliminated the AIR system. Interestingly, the AIR solenoid valve was defective and likely never actually operated.
With respect to tune up, it is a good point, but since the vehicle passed the 2500rpm test I have assumed (perhaps incorrectly) that the engine is operating nominally. I am replacing the plugs with the recommended AC Delco parts, but not planning on replacing distributor parts. Timing is set at 0deg when EST is disconnected.

Anyone have feedback on my idea to force closed loop idle by feeding a VSS signal above 4mph? Not convinced that is a good solution... I would only use this in the short term (I am convinced the right long term solution is to tune the calibration file per In-Tech’s experience).
thanks!
-Adam